implement fixed width printing

c_os/devices/CGA_Stream.h

@@ -19,15 +19,15 @@
 #include "lib/OutStream.h"
 
 class CGA_Stream : public OutStream, public CGA {
-    
+
 private:
-      CGA_Stream(CGA_Stream &copy); // Verhindere Kopieren
+    CGA_Stream(CGA_Stream &copy); // Verhindere Kopieren
 
 public:
     CGA_Stream () : OutStream(), CGA() { flush(); }
 
     // Methode zur Ausgabe des Pufferinhalts der Basisklasse StringBuffer.
-    virtual void flush ();
+    void flush () override;
 };
 
 #endif

c_os/lib/OutStream.cc

@@ -22,15 +22,64 @@
 
 #include "lib/OutStream.h"
 
+// NOTE: I added this, stream manipulators with arg
+OutStream& OutStream::operator << (const fillw& w) {
+    this->fill_width = w.w;
+    return *this;
+}
+OutStream& OutStream::operator << (const fillc& c) {
+    this->fill_char = c.c;
+    return *this;
+}
+
+// NOTE: I added this, fixed width printing
+void OutStream::put(char c) {
+    if (this->fill_width == 0) {
+        StringBuffer::put(c);
+    } else if (this->fill_used == this->fill_width - 1) {
+        // This indicates that content has been cut
+        StringBuffer::put('@');
+        this->fill_use_char();
+    } else if (this->fill_used == this->fill_width) {
+        // do nothing
+    } else {
+        StringBuffer::put(c);
+        this->fill_use_char();
+    }
+}
+void OutStream::fill_finalize() {
+    if (this->fill_width == 0 || this->fill_used == this->fill_width) {
+        // do nothing
+    } else if (this->fill_used > this->fill_width) {
+        // should never happen
+    } else {
+        for (unsigned char i = 0; i < this->fill_width - this->fill_used; ++i) {
+            StringBuffer::put(this->fill_char);
+        }
+    }
+
+    this->fill_used = 0;
+}
+void OutStream::fill_use_char() {
+    if (this->fill_width == 0) {
+        return;
+    }
+    this->fill_used++;
+}
 
 //
 // Zeichen und Zeichenketten in Stream ausgeben
 //
 OutStream& OutStream::operator << (char c) {
     put(c);
+    if (c != '\n') {
+        // endl() doesn't has access to StringBuffer::put(), so ignore \n here
+        this->fill_finalize(); // NOTE: I added this
+    }
     return *this;
 }
 
+// TODO: shouldn't this be printed as number?
 OutStream& OutStream::operator << (unsigned char c) {
     return *this << (char) c;
 }
@@ -41,6 +90,7 @@ OutStream& OutStream::operator << (char* string) {
         put (*pos);
         pos++;
     }
+    this->fill_finalize(); // NOTE: I added this
     return *this;
 }
 
@@ -79,10 +129,10 @@ OutStream& OutStream::operator << (long ival) {
 OutStream& OutStream::operator << (unsigned long ival) {
     unsigned long div;
     char digit;
-   
+
-    if (base == 8)
+    if (base == 8) {
         put ('0');         // oktale Zahlen erhalten eine fuehrende Null
-    else if (base == 16) {
+    } else if (base == 16) {
         put ('0');         // hexadezimale Zahlen ein "0x"
         put ('x');
     }
@@ -94,12 +144,14 @@ OutStream& OutStream::operator << (unsigned long ival) {
     // ziffernweise Ausgabe der Zahl
     for (; div > 0; div /= (unsigned long) base) {
         digit = ival / div;
-        if (digit < 10)
+        if (digit < 10) {
-                put ('0' + digit);
+            put ('0' + digit);
-        else
+        } else {
-                put ('a' + digit - 10);
+            put ('a' + digit - 10);
+        }
         ival %= div;
     }
+    this->fill_finalize(); // NOTE: I added this
     return *this;
 }
 
@@ -130,7 +182,7 @@ OutStream& OutStream::operator << (OutStream& (*f) (OutStream&)) {
 // Fuege einen Zeilenumbruch in die Ausgabe ein.
 OutStream& endl (OutStream& os) {
     os << '\n';
-    os.flush ();
+    os.flush();
     return os;
 }
 

c_os/lib/OutStream.h

@@ -7,13 +7,13 @@
  *                  << Operators fuer die wichtigsten der vordefinierten     *
  *                  Datentypen und realisiert somit die bekannte Ausgabe-    *
  *                  funktion der C++ iO_Stream Bibliothek. Zur Zeit wird     *
- *                  die Darstellung von Zeichen, Zeichenketten und ganzen    * 
+ *                  die Darstellung von Zeichen, Zeichenketten und ganzen    *
  *                  Zahlen unterstuetzt. Ein weiterer << Operator erlaubt    *
  *                  die Verwendung von Manipulatoren.                        *
  *                                                                           *
  *                  Neben der Klasse OutStream sind hier auch die            *
  *                  Manipulatoren hex, dec, oct und bin fuer die Wahl der    *
- *                  Basis bei der Zahlendarstellung, sowie endl fuer den     * 
+ *                  Basis bei der Zahlendarstellung, sowie endl fuer den     *
  *                  Zeilenumbruch definiert.                                 *
  *                                                                           *
  * Autor:           Olaf Spinczyk, TU Dortmund                               *
@@ -24,17 +24,51 @@
 
 #include "lib/StringBuffer.h"
 
+// NOTE: I added this, stream manipulator with argument
+class OutStream;
+
+// TODO: Should this only work for the next << ?
+class fillw {
+public:
+      fillw(unsigned char w) : w(w) {};
+      unsigned char w;
+};
+
+class fillc {
+public:
+      fillc(char c) : c(c) {};
+      char c;
+};
+
+
 class OutStream : public StringBuffer {
-    
+
 private:
       OutStream(const OutStream &copy); // Verhindere Kopieren
 
+      // NOTE: I added this
+      unsigned char fill_used; // indicates how many characters are already used by the text internally
+      void fill_use_char(); // recognizes that one char from the print width has been used up
+      void fill_finalize(); // does the filling after text has been written to buffer
+
 public:
       int base;   // Basis des Zahlensystems: z.B. 2, 8, 10 oder 16
 
-      OutStream () : StringBuffer () { base = 10; }   // initial Dezimalsystem
+      // NOTE: I added this
+      unsigned char fill_width;
+      char fill_char; // fill character for fixed width
 
-      virtual void flush () = 0;                    // weiterhin undefiniert
+      OutStream () : StringBuffer () {
+            base = 10;   // initial Dezimalsystem
+            fill_width = 0;   // no fixed width
+            fill_used = 0;
+            fill_char = ' ';  // fill with spaces
+      }
+
+      void flush() override = 0; // weiterhin undefiniert aber public
+
+      // NOTE: I added this
+      void put(char c) override;
 
       // OPERATOR << : Umwandlung des angegebenen Datentypes in eine
       //               Zeichenkette.
@@ -57,9 +91,12 @@ public:
       // Darstellung eines Zeigers als hexadezimale ganze Zahl
       OutStream& operator << (void* ptr);
 
+      // NOTE: I added this, set fixed output width
+      OutStream &operator << (const fillw &w);
+      OutStream &operator << (const fillc &c);
+
       // Aufruf einer Manipulatorfunktion
       OutStream& operator << (OutStream& (*f) (OutStream&));
-    
 };
 
 

c_os/lib/StringBuffer.h

@@ -36,8 +36,9 @@ protected:
     // StringBuffer: Im Konstruktor wird der Puffer als leer markiert.
     StringBuffer () : pos(0) {}
 
+    // NOTE: I changed this 
     // Fuegt ein Zeichen in den Puffer ein. Wenn der Puffer
-    void put (char c);
+    virtual void put (char c);
 
     // Methode zur Ausgabe des Pufferinhalts
     virtual void flush () = 0;